The present invention relates to a starting device for an engine in which a drive shaft associated with a starting motor is connected through a one-way clutch to a pinion gear for driving a ring gear of the engine. It is an object of the invention to provide a simple and effective starting device as described wherein if at the time of start, engagement between the pinion gear and the ring gear is improper, such engagement can be brought into a proper condition by the utilization of a turning force of the drive shaft, and if an excessive load is applied to the pinion gear, such a load can be absorbed to prevent the pinion gear and other transmission members from being damaged due to the excessive load.